The invention generally relates to belt buckles used for seat belts in automotive vehicles and, accordingly, to a casing shell for a belt buckle as well as a casing for a belt buckle including a casing shell and to a method of manufacturing a casing shell for such belt buckle.
The casing for a belt buckle and the casing shells forming the same typically are injection-molded parts made of plastic material. For manufacturing the injection-molded parts complicated injection molds are used which frequently include, apart from two tool members adjustable relative to each other, also slides so as to enable the manufacture of the required complicated molds of the casings.
In the contact area of the two tool parts the so called mold parting surface is located. Here inevitably the problem arises that irregularities such as unevenness, sharp edges, points or other irregularities are formed on the injection-molded part.
Such irregularities are undesired so that efforts have been made to avoid them. One approach consists in manufacturing the injection mold with especially high precision so as to avoid flashes. However, this results in particularly high manufacturing costs for the injection mold.